1. Field of the Invention
The present invention relates to a wireless communication device and feed-in method thereof, and more particularly, to a wireless communication device and feed-in method thereof for dual band transmission and reception.
2. Description of the Prior Art
Electronic products with wireless functions, such as wireless access points (APs) and laptops, transmit and receive radio-frequency (RF) signals through antennas to exchange wireless signals and access wireless network. Therefore, for facilitating users to access wireless network more easily, an ideal antenna should cover more frequency bands and size of the antenna should be reduced to meet a trend of light weight and small size of the electronic products.
A slot antenna is widely used in a conventional wireless device, and has a slot for resonating a single frequency band. However, if a wireless device requires operations of dual frequency bands, e.g. to conform to the IEEE 802.11a/b/g standards at the same time, it takes two single slot antennas to meet such a requirement, which increases antenna area and thus increases size of the wireless device. Moreover, if microstrip lines of the two single slot antennas are connected together to form a single feed-in point, the two single slot antennas influence each other, resulting in frequency shift phenomenon on both of the slot antennas. As a result, a signal diplexer is needed for solving frequency shift phenomenon. Furthermore, a conventional signal diplexer is formed by capacitors and inductances, which also increases the production cost.
As known from the above, there is a need to improve the conventional slot antenna to achieve a dual-band slot antenna to meet a trend of small size and low cost of the wireless electronic products.